There are some problems with this profile's children. From freereg the following children were baptised to Robert and Mercy. The list matches pretty closely with the profiles and census records but not exactly.
Robert William ROBERTS 23 May 1830 Strood : St Nicholas of Myra
Mary Ann ROBERTS 15 Jan 1832 Frindsbury : All Saints
Eliza Ann ROBERTS 24 Nov 1833 Frindsbury : All Saints
Mary Ann ROBERTS 25 Oct 1835 Strood : St Nicholas of Myra
William ROBERTS 10 Dec 1837 Strood : St Nicholas of Myra
Edward John ROBERTS 08 Mar 1840 Strood : St Nicholas of Myra
Caroline ROBERTS 09 Jan 1842 Frindsbury : All Saints
John Edward ROBERTS 06 Apr 1845 Frindsbury : All Saints
Harriett Maria ROBERTS 07 Mar 1847 Frindsbury : All Saints
So James seems to have been baptised as John Edward, Edward John and John should be merged and William John should be replaced by William b. 1837 (and seen aged 3 on the 1841 census).
Also when a profile source is familysearch could you just copy and paste the citation onto the profile like this:
"England and Wales Census, 1841," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:MQKV-P6T : 21 May 2019), Robert Roberts, Frindsbury, Kent, England, United Kingdom; from "1841 England, Scotland and Wales census," database and images, findmypast (http://www.findmypast.com : n.d.); citing PRO HO 107, The National Archives, Kew, Surrey
It only takes a second and makes it much easier for people to follow your research.